Transfer of Heat | Heat Transmission | Difference Between Heat and Temperature

Heat has a enormous influence in our daily lives. Heat quantity exposed in our live has related to the foods we eat, the temperature of our house and buildings, and clothes we wear. Heat can be transferred between different objects with different temperature. But do you know that heat is different from temperature?

Difference Between Heat and Temperature

The difference between heat and temperature are sometimes overlooked, yet they are so important. Most of the time heat is described as quantity measurement, and temperature is generally described as level of intensity. To recognize more clearly the difference between heat and temperature, assume that we put water with the same temperature on gallon bucket and gallon container. The heat of water on container will have less intensity compare to that heat on bucket. The temperature difference between the two is mainly because of molecules speed and movements in each enclosures are acted differently. Not only both are different in physics substance, but also quantification using different measurement. Heat is measured in British thermal units (Btu), whereas temperature difference is measured in degrees with a thermometer,

Heat Transmission

Let us now look how to make the best possible of heat and how to prevent heat loss. Heat is not static, it is transferred from one point to another. The transfer of heat between objects or areas is determined primarily by temperature. Heat must always flow from a warmer object (high temperature) to a colder object (low temperature). The transfer rate of flow depends on the difference between heat and temperature on both objects. For example, in your apartment building, heat may be flow from home basement to every room during winter. When it is summer time, heat is transferred from each room of a building to an area outside or away from the building.

Now, let us examined two different objects: one small object and one large object. Both are placed in an insulated box of suitable size. The smaller object has the temperature difference twice of the larger object. The heat level of the larger object is much greater than the smaller object, depending on the volume ratio of the two. In this case, heat will be flowed from smaller object to the larger one. It will continue to do so, until both have reached equal temperature or temperature difference of zero. How long the transfer heat between those adjoining objects will last? It is depends of the volume ratio of the two. Thus ,the transfer of heat from one location to another depends a great deal on the material of the flow path.

As you probably knew, heat can be transferred from one point to another by solids, gases and liquids. If one solid metal bar is put in flame, the other side will become hot at a matter of w few minutes. In this scene, transfer of heat, is achieved by conduction, convection and radiation.

Transfer of Heat: Conduction

In conduction, transfer of heat is transmitted from flame to the bar. For transfer of heat by conduction to take place, the heat source must touch the object being heated. This is take place because collision of molecules inside solid metal bar. Heat transfer by conduction is dependent on the material and its physical size. The conduction process applies primarily to transfer of heat through solid materials. Metals are the best conductors of heat, whereas nonmetals in general are poor conductors of heat or heat insulators. Daily activity like cooking and food preparation rely heavily on the transfer of heat by conduction.

Transfer of Heat: Convection

Convection is another term of heat transfer by using fluid substance like liquid or gas as a media for transferring heat. Convection is the process of transmitting heat through a fluid such as a liquid or a gas. When a container of water supply is put on a heat source, initially only the water at the bottom encounters heat up by conduction by the container. As nearly all liquids are quite poor conductors oh heat, only small amount of heat is transferred to a different parts of the liquid. When the bottom level of water gets to experience heat, it tends to expand somewhat. This circumstance causes them to get less dense than the cooler water on above position. Because a result of this condition, warm water starts to rise to the surface, which causes heavier cold water to fall down towards the source of heat. The new bottom layer of water will experience heat, expand, and ascend to the top of the container in the same manner as before. Each layer of liquid runs gradually downward, receives heat, and then rises to the top of the container. If the heat source is continued, the process is repeated over and over again until boiling occurs.

Transfer of Heat: Radiation

The last method of heat transfer is radiation. In this process, heat transfer by the motion of waves. The perfect example of radiation of heat transfer is how heat reaches earth from the sun. The space between sun and earth is generally consisted of void molecules, but near earth’s surface in started consisted some liquids. Its heat cannot be transferred by conduction or convection. The only way of heat energy can be transferred is through radiation with infrared rays. These rays possess discrete bundles of energy that are set into motion by the source. Energy of this type moves away from the source in a wavelike pattern at the speed of light. An interesting characteristic of radiation is that the air between the heat source and the object, which the waves must pass through, is not heated.